1. Field of the Invention
The present invention relates to a decorative sheet, which is used for covering portions of an article, where people may touch, for example, exteriors of various electronic equipment such as a personal digital assistant, OA equipment, AV equipment, and a household electrical appliance, interiors of automobiles, interior construction materials, stationery, and daily necessities, and is capable of imparting a soft feeling to the article when being touched (hereinafter, referred to as “soft touch feeling”), a decorative molded body, a decorative key sheet, and a decorative sheet manufacturing method.
2. Description of the Related Art
The exteriors of some articles, for example, various electronic equipment such as a personal digital assistant and a household electrical appliance, and the interiors of some automobiles are decorated with a soft material to provide a user with a soft touch feeling, thus adding a quality appearance to such articles for enhancement in design value and differentiation.
For example, JP 05-221271 A and JP 2000-158463 A each disclose a skin material imparting a soft touch feeling to automotive interior components. The skin material exhibits a laminate structure including an outer layer formed of a solid layer and an inner layer formed of a foamed layer, and is formed by powder slush molding.
Further, JP 05-84775 A, JP 05-98041 A, and JP 06-254885 A each disclose a technology for obtaining a molded product with a soft touch feeling through integration of a soft touch sheet and a molding resin. In this soft touch sheet, foaming beads, hollow beads, elastic particles, or the like are mixed in a resin, and the composition thus obtained is formed into a sheet through coating or drawing; further, a foamed resin layer is stacked thereon. Then, this soft touch sheet is inserted into a mold for injection molding to perform resin injection molding, thereby obtaining a molded product through integration of the soft touch sheet with a resin molded body. As compared with a case of later-attaching the soft touch sheet onto a surface of the resin molded body, the above manufacturing technology, in which integration is thus effected through insert molding, is more advantageous in that a working efficiency thereof is excellent and the manufacturing is easy.
Incidentally, when applying to a product the skin material as disclosed in JP 05-221271 A and JP 2000-158463 A described above, and the soft touch sheet as disclosed in JP 05-84775 A, JP 05-98041 A, and JP 06-254885 A, the skin material and the soft touch sheet, which are in the form of sheets, are cut and attached to the external surface of the product main body. Then, a foamed layer or a foamed resin layer appears in the side surface of the edge portion of the cut skin material and of the soft touch sheet. The foamed layer and the foamed resin layer are each fragile and inferior in chemical resistance. Accordingly, when actually used with the foamed layer or the foamed resin layer exposed, the edge portion will suffer breakage, and there is a fear of the breakage gradually expanding from the edge portion. For example, when applied to a mobile (cellular) phone, the edge portion will be rubbed by fingers or clothes of a user to scrape off the foamed layer or the foamed resin layer, and sweat, hand cream or the like will be liable to adhere to the edge portion to erode the foamed layer or the foamed resin layer; in this way, the edge portion of the skin material and of the soft touch sheet will suffer breakage, with the damaged portion gradually expanding.